Posted by: Major Dan (markj89@charter.net) on Wed Sep 12 08:55:45 2001

>>> My views on this may be somewhat idiosyncratic, but here goes. Much of this is more in terms of teching "cues" rather than reality.
> >
> > The primary center of "feel"/proprioception/control of the lower body motion is in the hips. Good " balance" and supporting positions of the feet must be learned, but focussing primarily on the feet or legs is like the tail trying to wag the dog and will not result in adequate hip rotation. I like the feel of "striding to balance", then "dropping the front heel" as a "trigger" for a strong "hip turn". I think these cues encourage good separation and powerful hip turn. Pushing from the back cues do not work as well as they often discourage separation of upper and lower half or swaying motion rather than balanced rotation of the body (rotation around a stationary axis as Jack describes it). Sometimes I do add the cue of "driving the back knee forward" as a way of teaching the feel of more powerful hip turn. I also teach windmill fastpitch pitching which has very similar lower body action using the same cues of front foot plant "triggering " hip turn sometimes assisted by "back knee drive" if hip turn is weak. The pitchers do not have the added task of having to react to the pitch by varying front leg action/timing.
> >
> > More theoretically speaking, what I see on video of "optimum" home run swings is usually incredibly fast "hip snap". Look at the recent ESPN clip of the first 60 of Bond's homers to get a feel of how he rotates the body. When this happens in many power hitters(Bonds is an exception because the way he sets up his body's axis of rotation, he usually stays on the back toe)they come up on the back toe, then hip turn decelerates whipping momentum into the torso. The back toe then drags behind the front foot with reactive torque as momentum goes into the torso, then into turning the bat as long as the circular handpath is maintained. This toe drag is quite pronounced in some-Mantle and Aaron, for example. The toe drag stops and the back hip falls back(accentuating the prior "up" thrust of the hips before this)when the hands cast away from the axis of rotation with a second wave of reactive torque going down the back leg and turning the back ankle back. This second kind of reactive torque is the only kind seen in "upper body swings" in those hitters who do not separate the upper and lower half then sequentially transfer momentum from the ground up like the prferred "lower body" hitters do.
> >
> > Back toe drag is usually a sign of good momentum transfer in a "lower body" swing. The absence of toe drag is not necessarily significant. Dragging the toe is not a useful cue in my experience, but can be important in video analysis. <<<
> >
> > Hi Tom
> >
> > I doubt that it is surprising to you that I do not place the importance on hip to shoulder separation that you and Mike do. It is not that I haven't charted the swing of some good hitters with a lot of separation, because I have. But, at the same time, I have charted equally as good hitters with much less separation.
> >
> > I strongly believe that separation is essential in setting up a good launch position. "The inward turn" as coined by Ted Williams, is important in bringing the hands to the proper position and stretching the torso muscles for contraction. But I can find no benefit to separation attained from further opening of the hips during the stride. I am sure you have sound reasons for your position and I am always looking to learn.
> >
> > The answer to a couple of question would help me better understand your position.
> > --- Let us assume that two batters have the same rate of angular displacement of the shoulders. If one of the batters attained 20 degrees more separation (hips to shoulders) before shoulder rotation began, why would he generate a more powerful swing?
> > --- If two batters kept their lead arm in the same relationship to the rotating body, why would more separation of the hips be required to generate a circular hand-path?
> >
> > I look forward to a good discussion.
> >
> > Jack Mankin
> >
>
> Jack-
>
> I think some separation and closing are important to permit both transfer of momentum and rotation around a stationary axis.Turning the body "in one piece" seems to inevitably give a swaying motion rather than ground up rotation/momentum transfer.The amount of separation is probably more dependent on an individuals unique anatomy/physiology.Theoretically,the more separation you create and the faster you "unseparate",the more power you can generate,however,the intricacies of the motor system are much more complex.
>
> I would summarize by saying some separation is necessary,but more is not necessarily better.
>
> Epstein does believe there is some direct benefit to increased/max separation and states heuristically that more than 30 degrees "torque angle" means more than 30 homers.Of course,these are people who are already surviving in the majors,and I doubt he has done the detailed video analysis you have.He also states that slim build players separate more than the "thick" ones.

Tom - well stated.
To all -
The key concept here IMO is that 'separation' or 'torque angle' is a primary component of transfer mechanics. If the hips and shoulders turn together (unit turn) the shoulders will not turn any faster than the hips. This would result in a low rate of angular displacement of the shoulders. The value of separation is using that separation as part of the kinetic chain to accelerate the shoulders to a greater rate of angular displacement as the hips decelerate. This is done through transfer mechanics. Jack, your question is somewhat loaded. If different amounts of torque angle create the same rate of angular displacement of the shoulders, then there will be no difference in batspeed due to the torque angle. However it may take one body type 20 deg more to get a specific rate of angular displacment of the shoulders than another body type. This could be due to body type, relative strengths and weaknesses of torso muscles, etc.
I think a better question is: Can a hitter increase the rate of angular displacment of the shoulders by increasing torque angle?
I suggest that the answer is probably 'yes' as long as his body transfer that energy. The answer is 'no' after that point where the body is unable to transfer any more than it already is.
I also suggest that many hitters can improve batspeed in this area because many do not have enough separation. I don't see to many who are creating too much/wasted torque angle but it could happen.
I also think hitters can improve batspeed by more efficient transfer mechanics through conditioning and training.
I suspect Epstein's 30 degrees is an approximation but if we take that number as a guideline, then it says that good athletes with efficient transfer mechanics will have major league homerun power with 30 degrees of separation. You can do it with less (strength vs. elasticity) and its hard to get more than 40+ degrees (can't track the ball with your head backwards).
Tom, I think your last response explains all this very well.